AEDs have saved many lives in non-hospital settings, and, as a result of advances in AED technology, the number of lives saved per year is rising. An AED is a battery-operated device that analyzes a patient's heart rhythm, and, if appropriate, administers an electrical shock (automated) or instructs an operator to administer an electrical shock (semi-automated) to the patient via electrode pads. For example, such a shock can often revive a patient who is experiencing ventricular fibrillation (VF).
As discussed below in conjunction with FIG. 1, AEDs often require periodic maintenance by the customer, i.e., “in the field”. For example, one typically replaces the electrode pads after each use or after a specified period of nonuse, and replaces the battery when it is depleted.
Unfortunately, AEDs often require different types of field maintenance at different intervals, and some types of field maintenance are relatively expensive. For example, the life of the electrode pads is typically unrelated to the life of the battery. Therefore, one typically replaces the pads and the battery at different times. Furthermore, because of the power requirements of an AED, a replacement battery is often relatively expensive.
FIG. 1 is a perspective view of a conventional AED system 10, which includes an AED 12 for generating a defibrillation shock, defibrillator electrode pads 14a and 14b for providing the shock to a patient (not shown), and a battery 15. A connector 16 couples the electrode pads 14a and 14b to a receptacle 18 of the AED 12. Typically, the electrode pads 14a and 14b are sealed within a flexible, i.e., soft, package (not shown) that an operator (hands shown in FIG. 1) tears or peels open to access the electrode pads 14a and 14b. The package acts as a moisture barrier that prevents the electrode-pad contact gel (not shown) from prematurely drying out during storage of the electrode pads 14a and 14b. The battery 15, which typically is a lithium-ion battery, can provide relatively high power so that the AED 12 can quickly generate the defibrillation shock. The battery 15 and AED 12 may be stored separately, with the operator connecting the battery 15 to the AED 12 just prior to use in an emergency. Or preferably, the battery 15 and AED 12 may be stored together, with the battery 15 connected to the AED 12 during storage.
The AED 12 includes a main on/off key switch 22, a display 24 for displaying operator instructions, cardiac waveforms, or other information, a speaker 26 for providing audible operator instructions or other information, an AED status indicator 28, and a shock button 30, which the operator presses to deliver a shock to the patient (not shown). The AED 12 may also include a microphone 32 for recording the operator's voice and other audible sounds that occur during the rescue, and a data card 34 for storing these sounds along with the patient's ECG and a record of AED events for later study.
Still referring to FIG. 1, during an emergency where it is determined that the patient (not shown) may need a shock, the operator retrieves the AED 12 and installs the battery 15 if it is not already installed. Next, the operator removes the electrode pads 14a and 14b from the protective package (not shown) and inserts the connector 16 into the receptacle 18. Then, the operator turns the on/off switch 22 to the “on” position to activate the AED 12. Following the instructions displayed on the display 24 or “spoken” via the speaker 26, the operator places the electrode pads 14a and 14b on the patient in the respective positions shown in the pictures on the pads and on the AED 12. After the operator places the electrode pads 14a and 14b on the patient, the AED 12 analyzes the patient's ECG to determine whether the patient is suffering from a shockable heart rhythm. If the AED 12 determines that the patient is suffering from a shockable heart rhythm, then it instructs the operator to depress the shock button 30 to deliver a shock to the patient. Conversely, if the AED 12 determines that the patient is not suffering from a shockable heart rhythm, it informs the operator to seek appropriate non-shock treatment for the patient and often disables the shock button 30 so that even if the operator presses the button 30, the AED 12 does not shock the patient.
The AED system 10 typically requires periodic field maintenance to ensure that it is ready for emergency use at all times. Specifically, one replaces the battery 15 when the AED 12 determines that the charge stored in the battery has fallen below a predetermined level. If the AED system 10 delivers no more than a few defibrillation shocks while a particular battery 15 is installed, then this battery usually lasts for approximately five years before leakage or power drawn by the AED 12 (e.g., during periodic self-tests) drains the battery. Furthermore, one typically replaces the pads 14a and 14b after use—merely opening the pad package (not shown) typically constitutes use—or when they are no longer viable. For example, if the pads 14a and 14b are unopened, they usually have a shelf life of one to three years before the contact gel (not shown) dries out or the pads otherwise degrade from heat exposure or other causes.
Unfortunately, because it is impractical to perform all of the field maintenance at the same time, one typically performs different aspects of the maintenance at different times. For example, if the AED system 10 is not used, then one typically replaces the pads 14a and 14b every one to three years and replaces the battery 15 every five years. Although one could eliminate separately replacing the battery 15 by prematurely replacing the battery whenever he/she replaces the pads 14a and 14b, the high cost (approximately $80–$100) of the battery 15 makes this impractical.
Consequently, a need exists for an AED system that makes it more practical to perform different aspects of the field maintenance at the same time. Furthermore, a need exists for an AED system that allows one to perform different aspects of the field maintenance by replacing a single component. In addition, a need exists for an AED system that reduces the cost of maintenance.